Automated Smear Making Apparatus

ABSTRACT

An automated smear making apparatus used to prepare and smear samples on glass slides. In one embodiment, there is provided a smearing subsystem that generally includes a smear cartridge having: an input reel; at least one roll bar; a take-up reel; and a smearing tape. The smearing tape is initially wound within the input reel and coupled to the take-up reel such that the smearing tape can be drawn from the input reel and into the take-up reel. The smearing tape may include a plurality of perforations formed therein. The smearing tape may then be wrapped around the roll bar such that each of the plurality of perforations forms a blade that extends from the smearing tape to expose a smear surface as the smearing tape is drawn into the take-up reel. Alternatively, the smearing tape may be bent such that an edge of the smearing tape forms a smear surface between two roll bars. A slide transport surface is also provided to move a slide across the smear surface.

CROSS REFERENCE TO RELATED APPLICATIONS

Under 35 U.S.C. §119(e), this application claims priority to the filingdate of U.S. Provisional Patent Application Ser. No. 61/581,032, filedon Dec. 28, 2011, the disclosure of which application is hereinincorporated by reference in its entirety.

BACKGROUND

The present disclosure generally provides an automated smear makingapparatus used to prepare and smear samples (e.g., blood samples) onmicroscope slides. In one embodiment, there is provided a smearingsubsystem for use in an automated slide preparation apparatus. Thesmearing subsystem generally includes a smear cartridge having an inputreel, a deflection component, a take-up reel, and a smearing tape toform a smear surface. The smearing tape is initially wound within theinput reel and coupled to the take-up reel such that the smearing tapecan be drawn from the input reel and into the take-up reel. The smearingtape may include a plurality of perforations formed therein. Thesmearing tape may then be deflected by the deflection component suchthat each of the plurality of perforations forms a blade that extendsfrom the smearing tape to expose a smear surface as the smearing tape isdrawn into the take-up reel. In an alternative embodiment, an edge ofthe smearing tape may be used to form the smear. For example, thesmearing tape may be manipulated such that an edge of the smearing tapeforms a smear surface between a first and a second deflection component.The angle between the smearing tape edge and the slide may be adjustedeither by a mechanical mechanism or by the first and/or seconddeflection components. A slide transport surface is also provided tomove a microscope slide across the smear surface.

Additional embodiments and details are provided below.

SUMMARY

In some embodiments, the present disclosure provides a smearingsubsystem for use in an automated slide preparation apparatus, thesmearing subsystem including a smear cartridge including an input reel,a take-up reel, a smearing tape having a plurality of perforationsformed therein, wherein the smearing tape is initially wound within theinput reel and coupled to the take-up reel such that the smearing tapecan be drawn from the input reel into the take-up reel, a deflectioncomponent configured to deflect each of the plurality of smearing tapeperforations to create a blade that extends from the smearing tape toexpose a smear surface as the smearing tape is drawn into the take-upreel, and a slide transport surface configured to move a slide acrossthe exposed smear surface.

In some embodiments, the blade forms an acute angle with the slide whenthe slide transport surface brings the slide in contact with the exposedsmear surface. In some embodiments, the smearing subsystem furtherincludes an angle-control mechanism to adjust the acute angle formedbetween the blade and the slide. In some embodiments, the angle-controlmechanism is configured to adjust the position of the deflectioncomponent with respect to the input reel. In some embodiments, theangle-control mechanism is configured to adjust the position of thedeflection component with respect to the take-up reel. In someembodiments, the angle-control mechanism includes a step motorconfigured to move the deflection component. In some embodiments, theangle-control mechanism is configured to adjust the position of theinput reel with respect to the deflection component. In someembodiments, the angle-control mechanism is configured to adjust theposition of the take-up reel with respect to the deflection component.In some embodiments, the acute angle is less than about 60 degrees. Insome embodiments, the acute angle is less than about 45 degrees. In someembodiments, the acute angle is less than about 30 degrees. In someembodiments, the acute angle is less than about 15 degrees.

In some embodiments, the present disclosure provides a smearingsubsystem for use in an automated slide preparation apparatus, thesmearing subsystem including a smear cartridge including an input reel,a first and a second deflection component, a take-up reel, a smearingtape, wherein the smearing tape is initially wound within the input reeland coupled to the take-up reel such that the smearing tape can be drawnfrom the input reel into the take-up reel, and wherein the smearing tapeis disposed around the first and second deflection components, betweenthe input reel and the take-up reel such that an edge of the smearingtape forms a smear surface between the first and the second deflectioncomponents, and a slide transport surface configured to move a slideacross the smear surface. In some embodiments, the first and the seconddeflection components bend the smearing tape such that an acute angle isformed between the smearing tape and the slide when the slide transportsurface brings the slide in contact with the smear surface. In someembodiments, the smearing subsystem further includes an angle-controlmechanism to adjust the bend of the smearing tape between the first andthe second deflection components. In some embodiments, the angle-controlmechanism is configured to adjust the position of one of the first orthe second deflection component. In some embodiments, the angle-controlmechanism is configured to adjust the position of both the first and thesecond deflection components. In some embodiments, the first and thesecond deflection components are parallel to one another. In someembodiments, the movement of the slide transport surface isperpendicular to the smearing tape. In some embodiments, the acute angleis less than about 60 degrees. In some embodiments, the acute angle isless than about 45 degrees. In some embodiments, the acute angle is lessthan about 30 degrees. In some embodiments, the acute angle is less thanabout 15 degrees. In some embodiments, the first deflection componentcomprises a roll bar, and the smearing tape is wrapped around the rollbar between the input reel and the take-up reel. In some embodiments,the second deflection component comprises a roll bar, and the smearingtape is wrapped around the roll bar between the input reel and thetake-up reel.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated herein, form part ofthe specification. Together with this written description, the drawingsfurther serve to explain the principles of, and to enable a personskilled in the relevant art(s), to make and use the systems and methodspresented. In the drawings, like reference numbers indicate identical orfunctionally similar elements.

FIG. 1 is a perspective view of an automated slide preparationapparatus.

FIG. 2 illustrates a smearing subsystem for use in an automated slidepreparation apparatus.

FIG. 3 is a perspective view of the smearing subsystem of FIG. 2.

FIGS. 4A and 4B show a perspective view of a smearing cartridge inaccordance with one embodiment presented.

FIGS. 5A and 5B show a schematic illustration of an input reel,deflection component, take-up reel, and smearing tape.

FIG. 6 is a schematic illustration describing one embodiment presented.

FIG. 7 is a side view of a smearing cartridge in accordance with anotherembodiment presented.

FIG. 8 is a schematic illustration of another embodiment presented.

DETAILED DESCRIPTION

The present invention relates to automated slide preparation systemsused to prepare, smear, and image samples (e.g., blood samples) onmicroscope slides. In one particular embodiment, there is provided alow-cost smearing subsystem for use in an automated slide preparationsystem. Such smearing subsystem employs a reel-to-reel configuration toprovide a single use smear surface from a smearing tape (or ribbon).More specifically, a smearing tape, which is initially wound within aninput reel, is configured to provide multiple smearing edges (orsurfaces) for the smearing of a series of slides, as it is unwound fromthe input reel and drawn into a take-up (or waste) reel. Thereel-to-reel configuration is indexed to move (or advance) the tape suchthat a subsequent, clean smear surface is provided for a subsequentslide. As such, the smearing subsystem prevents cross-contamination, andpossible operator biohazard, by continuously providing clean, single-usesmear surfaces. Various embodiments are described below.

For example, in one embodiment, the smearing subsystem generallyincludes a smear cartridge having an input reel, a deflection component,a take-up reel, and an indexed smearing tape. The smearing tape isinitially wound within the input reel. The smearing tape is coupled to(or at least partially wound within) the take-up reel such that thesmearing tape can be drawn from the input reel into the take-up reel. Inone embodiment, the smearing tape may include a plurality ofperforations formed therein. The smearing tape is then wrapped around(or otherwise disposed on or stretched around) the deflection componentsuch that each of the plurality of perforations creates a blade thatextends from the smearing tape to expose a smear surface as the smearingtape is drawn into the take-up reel. In an alternative embodiment, anedge of the smearing tape may be used to form the smear. For example,the smearing tape may be manipulated such that an edge of the smearingtape forms a smear surface between a first and a second deflectioncomponent. The angle between the tape edge and the slide may be adjustedeither by a mechanical mechanism or by the first and the seconddeflection components. In some embodiments, the first and/or the seconddeflection components may comprise a roll bar, and the smearing tape maybe wrapped around (or otherwise disposed on, mounted on, or wound orstretched around) the roll bar. A slide transport surface is alsoprovided to move a microscope slide across the smear surface.

The following detailed description of the figures refers to theaccompanying drawings that illustrate one or more exemplary embodiments.Other embodiments are possible. Modifications may be made to theembodiment described herein without departing from the spirit and scopeof the present invention. Therefore, the following detailed descriptionis not meant to be limiting.

FIG. 1 is a perspective view of an automated slide preparation apparatus100, which is used to deposit a sample (e.g., a blood sample) onto aslide 380 (e.g., a glass, plastic, quartz, or other microscope slide),smear the sample for optimal viewing, and/or stain and dry the sampleprior to imaging the slide. In the embodiment shown, the slidepreparation apparatus 100 includes a smearing cartridge 115, a sampleaspiration subsystem 120, a slide printer and barcode subsystem 125, anda slide transfer subsystem 130. In operation, the slide transfersubsystem 130 draws slides 380 from one or more slide holders 135, andtransports the slides 380 to the sample aspiration subsystem 120. At thesample aspiration subsystem 120, a drop of sample (e.g., blood) isapplied to the slide 380 via an aspiration probe 221. The aspirationsubsystem 120 may draw samples (and if necessary reagents) from one ormore tube rack inputs 140.

After the slide 380 has been processed through the smearing cartridge115, where the sample is smeared across the slide 380, the smeared slideis transported to a slide carrier (or cartridge) 355, which has one ormore empty locations to accommodate a slide 380. (A plurality of slidecarriers 355, having one or more empty locations to accommodate slides380, are maintained in holding area 145.) Next, the slide carrier 355,typically holding a plurality of smeared slides 380, is furtherprocessed through additional subsystems, such as a staining subsystem170 and/or a drying subsystem 165. In the staining subsystems, theslides 380 are subjected to various reagents and/or cleaning baths.Finally, the slides 380 are processed through an imaging subsystem 175,where the samples are imaged for viewing by a trained professionaland/or a computer-automated imaging analysis system.

FIG. 2 provides perspective view of the smearing subsystem 110 ofFIG. 1. More specifically, FIG. 2 shows additional details of the sampleaspiration subsystem 120, which includes an aspiration shuttle (orprobe) 221, an aspiration point 222, a wash block 223, and are-suspension unit 224. In operation, a slide 380 is drawn from theslide holders 135 (or externally prepared slide input mount 231). Alabel (or other indicia such as a barcode) may be applied to the slide380 within the printer and barcode subsystem 125. The slide 380 is thenmoved from the aspiration subsystem 120 to the smear cartridge 115 overa slide transport surface 216. After being smeared, the slide 380 ismoved to a slide carrier (or cartridge) 355, which may be indexed byrack in a vertical indexer 217. As the slides 380 are mounted onto theslide carrier 355, a drying fan 218 may be applied to the slides 380.

FIG. 3 provides another perspective view of the smearing subsystem 110of FIG. 1. More specifically, the arrows of FIG. 3 show the process flowof a slide 380 as it is taken from the slide holders 135, through thesample aspiration subsystem 120, the smearing cartridge 115, anddeposited onto the slide carrier 355. Additional details of the slidecarrier 355 are disclosed in U.S. Provisional Application No.61/581,037, the entire disclosure of which is incorporated by referenceherein.

FIG. 4A is a perspective view, and FIG. 4B is a bottom-side view of asmearing cartridge 115, in accordance with one embodiment presented. Asshown, a smear surface 481 is provided by a blade (or tab, orprojection) 487 extending from a smearing tape 482. The blade 487extends from the smearing tape 482 as the smearing tape is drawn fromthe input reel 483, around a deflection component, such as, e.g., a rollbar (or roller) 484, and into the take-up reel 485. In practice, thesmearing tape 482 may be indexed to provide controlled movement of thetape. A motor (such as a step motor) may be coupled to the take-up reel485 to provide the movement of the smearing tape 482. In someembodiments, an adjustment mechanism, such as, e.g., a motor or a brake,may be applied to the input reel 483 to provide appropriate tension onthe smearing tape 482. Adjustment mechanisms may also be provided toadjust the relative positioning between the input reel 483, thedeflection component(s), and/or the take-up reel 485.

FIGS. 5A and 5B show a schematic illustration of how the blades (ortabs, or projections) 487 extend from the smearing tape 482 as thesmearing tape wraps (or is otherwise disposed or stretched) around adeflection component. More specifically, a perforation (or cut-out) 588is created within the smearing tape 482 such that the change indirection of the smearing tape around the deflection component causesthe blade 487 to project (or extend) from the smearing tape 482, andthereby creates a single-use smear surface 481. The smear surface 481 isthen used to smear a drop of sample (e.g., blood) 586, which is disposedon a slide 580, as the slide transport surface moves the slide acrossthe smear surface 481. After the slide 580 has been smeared, thesmearing tape 482 is advanced by drawing the smearing tape into thetake-up reel 485. The blade 487 returns from its extended position asthe smearing tape 482 moves beyond the deflection component. The ensuingblade on the smearing tape 482 is then used for the next slide to beprocessed.

In one embodiment, the smearing tape 482 includes a plurality ofindexing holes for “tractor feeding” of the tape, which do not directlyinfluence the function of the blades 487. These indexing holes may beround, but their shape may change to slots to accommodate tolerances, oreven notches in the edge of the tape to prevent waste “slugs” ofmaterial needing to be removed in processing. The key aspect of theindexing is to provide a means for an accurate tape locationdetermination. In one embodiment, perforations (or cut-outs) to createthe blades create a flat section (i.e., inside “critical edge”) thatdictates the width of the smear. In one embodiment, the width of thesmear is 25 mm, with a critical edge 22 mm wide, and an R1.5 in eachcorner. In one embodiment, the critical edge is smooth and free ofburrs. In one embodiment, the perforation itself creates a 2.5 mmcut-out to create the blade profile. Such cut-out may be as small aspossible to minimize tape usage, and as large as possible to maximizepunch tooling robustness. The cut-out width dimension may also be zero(i.e., a shear cut). Cut-outs in the tape may be created by die-cutting,while several variants are available such as: flatbed kiss cuttingagainst sacrificial anvil using “steel rule” die; rotary kiss cuttingagainst anvil using one-sided rotary die; rotary kiss cutting againstanvil and temporary “low tack” backing using one-sided rotary die;flatbed “match metal” or “male-female” die set; and/or rotary “matchmetal” or “male-female” die set.

Candidate materials for the smearing tape 482 include a number ofsemi-rigid thermoplastic polymers, including: Acrylonitrile ButadieneStyrene (ABS); polyethylene (PE; also known as: HDPE, MDPE, LDPE,LLDPE); polystyrene (PS); polypropylene (PP); polyurethane (PU);polyamide (PA, commonly known as Nylon); polyoxymethylene (POM, commonlyknown as Acetal or by trade name Delrin®); polycarbonate (PC);polytetrafluoroethylene (PTFE, commonly known by the trade nameTeflon®); polyethylene terephthalate (PET, commonly known as polyesteror by the trade names Mylar® or Melinex®); polyvinyl chloride (PVC,commonly known as Vinyl); poly-methyl methacrylate (PMMA, commonly knownas Acrylic or by the trade names Perspex® or Plexiglass®).

In some embodiments, the smearing tape may comprise a plastic film thathas a hydrophilic coating or a hydrophobic coating. In some embodiments,the smearing tape may comprise a plastic film that has been treated witha mild acid, such as, e.g., citric acid or isopropyl alcohol, tofacilitate good wicking and smearing of a sample onto a substrate, suchas a glass slide.

In some embodiments, the material for the smearing tape may be polyester(PET) because of its toughness and stability. Polyester film isavailable with a range of properties mainly in terms of optical clarityand treatment for adhesion to various substrates. The indirect influenceof surface finish is important in promoting wicking of the blood dropacross the width of the blade.

The length of the individual blades 487 (i.e., the “spine” area at theback of the blade) and the thickness of the smearing tape 482 materialmay dictate the stiffness of the blade 487 as well as the sensitivity toangular position as the smearing tape wraps around (or bends around, orcontacts) the deflection component. The gauge of the smearing tapematerial may be 175 μm (0.007″), while alternatives are available, suchas a range from 75-250 μm.

FIG. 6 is a schematic illustration describing one embodiment presented.More specifically, FIG. 6 shows the key angles and distances providedfor creating optimal smears, which may be affected by factors such asthe viscosity of the sample, hematocrit level of the sample, volume ofthe sample, etc. Smearing may also be sensitive to a number of differentparameters that will require tuning of the smearing subsystem to createsmears of acceptable quality. Said parameters may be adjusted based onthe relative position between the input reel, the deflectioncomponent(s), and/or the take-up reel. Parameters that may requireadjustment also include: distance between the deflection component(s)and the slide; indexing angle of the smearing tape; velocity profile ofthe slide; wicking position and time; perpendicularity of the smearingtape relative to the slide; blade pressure against the slide; and/orcentering of the blade on the slide.

The simplified geometry shown in FIG. 6 shows parameters defined asfollows:

θ=smear blade to slide contact angle

x=distance between front of deflection component and smear blade contacton slide

β=indexing angle between point P and blade tangent contact

s=arc length between point P and blade tangent contact

h=distance between deflection component center and slide surface (e.g.,8.5 mm)

l=smear blade length (e.g., 10 mm)

r=deflection component radius (e.g., 5 mm)

In one embodiment, it may be assumed that the blade 487 would extend ata perfect tangent from the deflection component (e.g., roll bar 484)when no slide is in place. However, when a slide 580 is inserted, thedistance between the deflection component and slide 580 is limited to h,causing the blade 487 to rotate around the tangent point, T. Incalculating the geometry, it is assumed that there is no flexing of theblade 487 and it pivots perfectly around the tangent point. In thiscase, the following geometry is used, when a certain contact angle, θ,is defined.

If l sin(θ)+r cos(θ)≧h, then:

β=sin⁻¹ ((h−l sin(θ))/r)

s=rβ

x=r−r cos(θ)+l cos(θ)

In one embodiment, the smearing tape 482 includes one or more opticalidentifiers or indicia (not shown) to identify the relative position ofthe smearing tape and or blades. In one embodiment, a distance along thesmearing tape between an optical identifier and point P is 16.9 mm, andthe distance between indexing holes in the smearing tape is 20.5 mm. Assuch, the smearing tape index distance, i, is: i=(s+16.9)mod 20.5. Inone embodiment, the distance along the slide between the home positionand the blood dispense location directly underneath point P is 73 mm.The smear start position, m, where the blade edge contacts the blood isthus: m=x+73

Calculations may be required to determine the number of steps requiredto index the smearing tape a certain distance given the changingdiameter of the input reel and take-up reel, as the smearing tape isadvanced. In this case, the size of the reel will follow the equation:

$R = \sqrt{\frac{Lt}{\pi} + r_{2}^{2}}$

where:

R=radius of reel with tape

L=used length of tape (e.g., number of smears×20.5 mm)

r₂=radius of waste reel core (e.g., 12.5 mm)

FIG. 7 is a side view of a smearing cartridge 715, in accordance withanother embodiment presented. As shown in FIG. 7, an input reel 783provides a smearing tape 782 that may be indexed for movement across aplurality of deflection components (e.g., roll bars 784). The smearingtape 782 may be advanced using a stepper motor (not shown) coupled tothe take-up (or waste) reel 785. In some embodiments, an adjustablebrake or other suitable component, such as, e.g., a motor (not shown)may be attached to the input reel 783 to set the proper tension to thesmearing tape 782. The smearing tape 782 may be punched with holes inthe side and/or painted with a silver paint pen so that an opticalsensor can be used to set the position of the smearing tape when anopening or painted indicia is sensed.

FIG. 8 is a schematic illustration of another embodiment presented. Asshown in FIG. 8, an input reel 883 provides an un-perforated smearingtape 882, which is wrapped around (or bent around, or stretched aroundor upon, or otherwise disposed about) a first and a second deflectioncomponent (e.g., two roll bars 884). The first and the second deflectioncomponents function to manipulate (e.g., bend, move, stretch, and ordeform) the smearing tape 882 such that an edge of the smearing tapeforms a smear surface 881 for smearing a sample on a slide 880. An anglecontrol mechanism 890 may be provided to adjust the angle of the smearsurface 881 appropriately. The angle between the smearing tape edge andthe slide 880 may be adjusted either by a mechanical mechanism and/orthe first and the second deflection components. In operation, a slidetransport surface moves the slide 880 perpendicularly (e.g., along thez-axis) across the smear surface 881.

ADDITIONAL EMBODIMENTS

In another embodiment, there is provided a method of smearing a samplein an automated slide preparation apparatus. The method includesproviding a smearing subsystem having: a smear cartridge including aninput reel, a deflection component (e.g., a roll bar), a take-up reel,and a smearing tape. In one embodiment, the smearing tape may include aplurality of perforations formed therein. The smearing subsystem may beconfigured such that the smearing tape is initially wound within theinput reel and coupled to the take-up reel so that the smearing tape canbe drawn from the input reel into the take-up reel. The smearing tapemay also be configured to wrap around the deflection component, betweenthe input reel and the take-up reel, such that each of the plurality ofperforations creates a blade that extends from the smearing tape toexpose a smear surface as the smearing tape is drawn into the take-upreel. The smear surface may then form an acute angle with the slide whenthe slide transport surface brings the slide in contact with the exposedsmear surface. In another embodiment, the smearing tape is bent betweena first and a second deflection component such that a side surface ofthe smearing tape creates the smear surface. The method may furtherinclude providing a slide transport surface configured to move a slideacross the exposed smear surface (be it the blade or the side of thebent smearing tape). The method may further include configuring thesmear cartridge such that the acute angle is less than about 60 degrees,less than about 45 degrees, less than about 30 degrees, and/or less thanabout 15 degrees. Such configuration may include moving the input reel,the first and/or the second deflection components, and/or the take-upreel with respect to one another. Such configuration may also includemonitoring the sample with an optical input subsystem (or other inputparameter) to adjust the acute angle depending on properties (e.g.,hematocrit level, viscosity, or volume) of the sample. The method mayfurther include adjusting: the distance between the first and/or thesecond deflection component and the slide; indexing angle of thesmearing tape; velocity profile of the slide; wicking position and time;perpendicularity of the smearing tape relative to the slide; and/orcentering of the blade on the slide.

The foregoing description of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed.Other modifications and variations may be possible in light of the aboveteachings. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,and to thereby enable others skilled in the art to best utilize theinvention in various embodiments and various modifications as are suitedto the particular use contemplated. It is intended that the appendedclaims be construed to include other alternative embodiments of theinvention; including equivalent structures, components, methods, andmeans.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or more,but not all exemplary embodiments of the present invention ascontemplated by the inventor(s), and thus, are not intended to limit thepresent invention and the appended claims in any way.

What is claimed is:
 1. A smearing subsystem for use in an automatedslide preparation apparatus, the smearing subsystem comprising: a smearcartridge including an input reel; a take-up reel; a smearing tapehaving a plurality of perforations formed therein, wherein the smearingtape is initially wound within the input reel and coupled to the take-upreel such that the smearing tape can be drawn from the input reel intothe take-up reel, and a deflection component configured to deflect eachof the plurality of smearing tape perforations to create a blade thatextends from the smearing tape to expose a smear surface as the smearingtape is drawn into the take-up reel; and a slide transport surfaceconfigured to move a slide across the exposed smear surface.
 2. Thesmearing subsystem of claim 1, wherein the blade forms an acute anglewith the slide when the slide transport surface brings the slide incontact with the exposed smear surface.
 3. The smearing subsystem ofclaim 2, further comprising an angle-control mechanism to adjust theacute angle formed between the blade and the slide.
 4. The smearingsubsystem of claim 3, wherein the angle-control mechanism is configuredto adjust the position of the deflection component with respect to theinput reel.
 5. The smearing subsystem of claim 3, wherein theangle-control mechanism is configured to adjust the position of thedeflection component with respect to the take-up reel.
 6. The smearingsubsystem of claim 3, wherein the angle-control mechanism includes astep motor configured to adjust the deflection component.
 7. Thesmearing subsystem of claim 3, wherein the angle-control mechanism isconfigured to adjust the position of the input reel with respect to thedeflection component.
 8. The smearing subsystem of claim 3, wherein theangle-control mechanism is configured to adjust the position of thetake-up reel with respect to the deflection component.
 9. The smearingsubsystem of claim 2, wherein the acute angle is less than about 60degrees.
 10. The smearing subsystem of claim 2, wherein the acute angleis less than about 45 degrees.
 11. The smearing subsystem of claim 2,wherein the acute angle is less than about 30 degrees.
 12. The smearingsubsystem of claim 2, wherein the acute angle is less than about 15degrees.
 13. The smearing subsystem of claim 1, wherein the deflectioncomponent comprises a roll bar.
 14. The smearing subsystem of claim 13,wherein the smearing tape is wrapped around the roll bar between theinput reel and the take-up reel.
 15. A smearing subsystem for use in anautomated slide preparation apparatus, the smearing subsystemcomprising: a smear cartridge including an input reel; a first and asecond deflection component; a take-up reel; a smearing tape, whereinthe smearing tape is initially wound within the input reel and coupledto the take-up reel such that the smearing tape can be drawn from theinput reel into the take-up reel, and wherein the smearing tape isdisposed around the first and the second deflection components betweenthe input reel and the take-up reel such that an edge of the smearingtape forms a smear surface between the first and second deflectioncomponents; and a slide transport surface configured to move a slideacross the smear surface.
 16. The smearing subsystem of claim 15,wherein the first and second deflection components bend the smearingtape such that an acute angle is formed between the smearing tape andthe slide when the slide transport surface brings the slide in contactwith the smear surface.
 17. The smearing subsystem of claim 16, furthercomprising an angle-control mechanism to adjust the bend of the smearingtape between the first and second deflection components.
 18. Thesmearing subsystem of claim 17, wherein the angle-control mechanism isconfigured to adjust the position of one of the first and seconddeflection components.
 19. The smearing subsystem of claim 17, whereinthe angle-control mechanism is configured to adjust the position of boththe first and the second deflection components.
 20. The smearingsubsystem of claim 15, wherein the first and second deflectioncomponents are parallel to one another.
 21. The smearing subsystem ofclaim 15, wherein the movement of the slide transport surface isperpendicular to the smearing tape.
 22. The smearing subsystem of claim15, wherein the acute angle is less than about 60 degrees.
 23. Thesmearing subsystem of claim 15, wherein the acute angle is less thanabout 45 degrees.
 24. The smearing subsystem of claim 15, wherein theacute angle is less than about 30 degrees.
 25. The smearing subsystem ofclaim 15, wherein the acute angle is less than about 15 degrees.
 26. Thesmearing subsystem of claim 15, wherein the first deflection componentcomprises a roll bar.
 27. The smearing subsystem of claim 15, whereinthe second deflection component comprises a roll bar.
 28. The smearingsubsystem of claim 26, wherein the smearing tape is wrapped around theroll bar between the input reel and the take-up reel.
 29. The smearingsubsystem of claim 27, wherein the smearing tape is wrapped around theroll bar between the input reel and the take-up reel.